<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>query</title>
</head>
<body>
<form action="query" method="POST">
    请输入问题：<input type="text" name="query">
    <br>
    答案：
    <br>
    <code>
      {{ans}}
    </code>

</form>
</body>
</html>